The present invention relates to a central tire inflation system and in particular to such an air inflation system for supplying air through a driven axle of a vehicle through a rotatable coupling.
It is known that tires on a vehicle, such as a truck trailer, should be properly inflated for ease of control of the vehicle, its safety, and to provide even wear and long life of the expensive tires. Various types of central tire inflation systems (CTIS) have been suggested in the past. However, one of the problems is to supply the air from a stationary air control system through a rotatable and sealable coupling for allowing rotation of the vehicle wheels while connected to the air control system.
The present invention is particularly useful for providing a rotatable air coupling for supplying air through the driven axle of a vehicle to tires thereon.